<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>公告</title>
        <style type="text/css">
            .wrapper{
                width: 80%;
                height: 500px;
                margin: 50px auto;
                background-color: salmon;
            }
            .wrapper marquee{
                height: 500px;
                color: white;
                text-align: center;
                margin: auto;
            }
            .notice{
                width: 400px;
                height: 200px;
                border: 3px solid #a4ff5d;
                margin: auto;
            }
        </style>
    </head>
    <body>
        <div class="wrapper">
            <marquee behavior="scroll" direction="up">
                <div class="notice">公告：明天下午两点上直播课</div>
            </marquee>
        </div>

    </body>
</html>